It was the bright, iridescent blue of the morpho butterfly that inspired Andrew Parnell and his colleagues. Struck by the insect’s natural ability to produce vibrant hues, the physicists and chemists began investigating how they too could produce eye-catching color—not with dyes, but by altering the structure of the material itself. “We could make these really nice reflectors, very much like the butterflies do, mimicking how nature makes them,” says Parnell, whose lab at the University of Sheffield, England, studies colors that span the rainbow.
A pigment produces color by absorbing all but a specific wavelength of light. By contrast, colors produced by altering the arrangement of molecules reflect only a specific wavelength. Parnell calls it the science of controlling light.
Blue pigments occur rarely in nature. But some 4,800 miles to the west of Parnell’s lab, at Oregon State University, materials scientist Mas Subramanian discovered a new blue pigment—by chance. Searching for a magnetic material that could store electricity and be used in computers, Subramanian and his graduate students stuck a mixture of the metallic elements yttrium, indium, and manganese into a furnace and were surprised to see that they’d created a bright blue substance. He named it YInMn, from the elements’ symbols.